1. Field of the Invention
The present invention relates to an article of furniture that is useful as a futon and which may also be easily converted into a bed or a chaise lounge.
2. Description of the Prior Art
A futon is generally considered to be an article of furniture that may be used as a bed, but which may be configured so as to have a back and bench shaped as a couch for occupancy, usually by a single person. Unlike a couch, a futon does not have arms on its sides.
Various articles of furniture have been constructed with a feature of convertibility whereby a futon can be converted to a bed. In such an arrangement the back of the futon is constructed so as to be alternatively oriented in a flat disposition relative to the seat bench, so as to form a flat bed. Alternatively, the back support section can be oriented to an upright, slightly inclined disposition relative to the seat bench so that the article of furniture becomes a futon.
Some prior devices have been constructed so that the seat bench portion of the furniture article slides or rolls into a frame, or is alternatively extended from a frame, depending upon whether the article of furniture is to serve as a futon or as a bed. However, all prior devices of this type are somewhat cumbersome to operate or inordinately expensive to build.
One object of the present invention is to provide an article of furniture that is convertible as between a bed and a futon in which the movable seat bench portion can be easily rolled into a stationary frame in such a manner as to easily, but releaseably latch in position relative to the outer, stationary frame. In addition, the article of furniture is constructed so that the seat bench latch will not readily become disengaged in an unexpected manner, but which can easily be purposefully disengaged to draw the seat bench out away from the outer frame, if desired.
A related object is the provision of a convertible futon bed in which the futon seat bench can be easily disengaged from the outer frame and rolled out away from the head frame of the outer support to collapse the portions of the base frame assembly into a flat bed frame. The seat bench can also easily rolled back in toward the head frame to create a futon seat back located behind the futon seat bench. The article of furniture of the invention is provided with cam latches that firmly, but releaseably secure the futon seat bench in front of the seat back frame for use as a seating support.
Another object of the invention is to provide a roll-in futon that can alternatively be deployed as either a flat bed or a chaise lounge.
In one broad aspect the invention may be described as a convertible article of furniture comprising a stationary outer support and a movable base frame assembly. The outer support is formed with a central, transverse head frame from both ends of which mutually parallel side frames extend longitudinally in spaced separation from each other. The movable base frame assembly is supported on rolling members such as wheels, rollers, or casters, for longitudinally reciprocal movement relative to the stationary outer support and between the side frames. The movable base frame assembly has a longitudinally distal seat bench frame remote from the head frame and an intermediate back frame located between the seat bench frame and the head frame. The seat bench frame and the intermediate back frame are hinged to each other. The side frames of the stationary outer support are each provided with a roller located remote from the heat frame. The rollers are oriented for rotation about horizontal roller axes that are perpendicular to the side frames. The seat bench frame has a distal portion longitudinally remote from the head frame. The seat bench frame also has cam latches with arcuate, downwardly facing concave seating recesses defined therein projecting downwardly from its distal portion.
The cam latches include longitudinally oriented cam surfaces inclined in a direction downwardly and away from the head frame and toward the seating recesses. As a result, as the seat bench frame approaches the head frame, the cam surfaces ride up the rollers to elevate the longitudinally distal portion of the seat bench frame and then releaseably lodge the concave seating recesses upon the rollers. The seat bench frame and intermediate seat back frame are typically provided with a conventional cushioning pad so as to afford a measure of comfort to the user or users.
In another broad aspect the invention may be considered to be an improvement in an article of furniture having a stationary support with upright, mutually parallel opposing sides and a base frame assembly movable between the opposing sides and parallel thereto, and in which the base frame assembly includes a seat bench frame and at least an intermediate seat back frame hinged to the seat bench frame for rotational movement relative thereto. The seat bench frame is provided with supporting rolling members. The improvement of the invention is comprised of a roller on each of the sides of the stationary support. The rollers are oriented for rotation about axes perpendicular to the sides of the stationary supports. Also, cam latches are provided on opposing sides of the seat frame in longitudinal alignment with the rollers. The cam latches include concave downwardly facing seating recesses and cam surfaces inclined longitudinally and upwardly therefrom and toward the intermediate seat back frame. Consequently, when the seat bench frame is moved to engage the cam latches with the rollers, the cam surfaces of the cam latches ride up the rollers and the seating recesses lodge on the rollers in releaseable latching engagement therewith when moved into registration with the rollers.
In still another aspect, the invention may be considered to be a roll-in futon comprising: a stationary outer support and a movable base frame assembly. The stationary outer support is formed with a laterally extending head frame having opposing ends and a pair of mutually parallel side frames at the opposing ends of the head frame. The side frames extend in a footward direction from the head frame. Rollers are rotatably mounted on the side frames for rotation about axes perpendicular thereto. The movable base frame assembly includes a seat bench frame located in a footward direction from the head frame and at least an intermediate back support frame located between the head frame and the seat bench frame and joined by a footward hinge for movement relative to the seat bench frame. The movable base frame assembly also includes cam latches that project downwardly from the seat bench frame and include concave downwardly facing seating recesses and cam surfaces inclined upwardly therefrom and toward the head frame. The rollers engage the cam latches as the intermediate back support frame approaches the head frame, and the rollers lift at least a portion of the seat frame as the cam surfaces ride up the rollers. The seat frame is releaseably lodged relative to the stationary support when the rollers engage the concave seating surfaces of the cam latches.
Preferably, base frame assembly further includes a proximal back frame hinged to the intermediate back frame and located between the intermediate back frame and the head frame. The seat bench frame, the intermediate seat back frame, and the proximal seat back frame are joined together in articulated fashion. The proximal back frame is rotatably secured to the side frames at back frame axle pins located proximate the head frame for rotation relative to the side frames about a proximal back frame axis of rotation perpendicular to the side frames. When the article of furniture is converted to a bed, the proximal back frame lies immediately adjacent to the head frame with the intermediate back frame and the seat bench frame extending longitudinally therefrom in that order in a footward direction.
The cam latching mechanism of the convertible futon is an extremely important aspect of the invention. The cam surfaces of the cam latches are preferably formed on vertical cam plates and are inclined at an angle of between about twenty-five degrees and about forty-five degrees relative to the seat bench frame at the time the rollers first contact the cam surfaces. In the preferred embodiment this angle of inclination is about thirty-three degrees relative to the horizontal orientation of the seat bench frame.
Also, a proper selection of the size and configuration of the rollers and the seating recesses improves the smoothness of latching and unlatching the cam latching mechanism. The rollers have a contact surface diameter typically between about one-half inch and about one and one-half inches, preferably about seven-eighths of an inch. The concave recesses are both preferably shaped with a circular arc at a diameter of between about one and two inches. The arc of the seating recesses can vary somewhat, but normally is between about thirty and ninety degrees. In the preferred embodiment the circular arc of the concave seating recesses is formed at a diameter of about one and three-eighths inches and extends over a circular arc of about sixty degrees.